Stereotactic body radiotherapy for lesions of the spine and paraspinal regions.
Int J Radiat Oncol Biol Phys
; 73(5): 1369-75, 2009 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-19004569
ABSTRACT
PURPOSE:
To describe our experience and clinical strategy for stereotactic body radiotherapy (SBRT) of spinal lesions. METHODS AND MATERIALS Thirty-two patients with 33 spinal lesions underwent computed tomography-based simulation while free breathing. Gross/clinical target volumes included involved portions of the vertebral body and paravertebral/epidural tumor. Planning target volume (PTV) expansion was 6 mm axially and 3 mm radially; the cord was excluded from the PTV. Biologic equivalent dose was calculated using the linear quadratic model with alpha/beta = 3 Gy. Treatment was linear accelerator based with on-board imaging; dose was adjusted to maintain cord dose within tolerance. Survival, local control, pain, and neurologic status were monitored.RESULTS:
Twenty-one patients are alive at 1 year (median survival, 14 months). Median follow-up is 6 months for all patients (7 months for survivors). Mean previous radiotherapy dose to 22 patients was 35 Gy, and median interval was 17 months. Renal (31%), breast, and lung (19% each) were the most common histologic sites. Three SBRT fractions (range, one to four fractions) of 7 Gy (range, 5-16 Gy) were delivered. Median cord and target biologic equivalent doses were 70 Gy(3) and 34.3 Gy(10), respectively. Thirteen patients reported complete and 17 patients reported partial pain relief at 1 month. There were four failures (mean, 5.8 months) with magnetic resonance imaging evidence of in-field progression. No dosimetric parameters predictive of failure were identified. No treatment-related toxicity was seen.CONCLUSIONS:
Spinal SBRT is effective in the palliative/re-treatment setting. Volume expansion must ensure optimal PTV coverage while avoiding spinal cord toxicity. The long-term safety of spinal SBRT and the applicability of the linear-quadratic model in this setting remain to be determined, particularly the time-adjusted impact of prior radiotherapy.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Coluna Vertebral
/
Radiocirurgia
Tipo de estudo:
Evaluation_studies
/
Prognostic_studies
Limite:
Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article